v2.42.0: Error Prone 2.42.0

New checks:

• ExplicitArrayForVarargs: discourage unnecessary explicit construction of an array to provide varargs.
• FloggerPerWithoutRateLimit: discourage Flogger's perUnique without rate limiting
• StringJoin: Ban String.join(CharSequence) and String.join(CharSequence, CharSequence)
• ThreadBuilderNameWithPlaceholder: Do not allow placeholders in Thread.Builder.name(String) or name(String, int).

Changes:

• The return type of ASTHelpers.asFlagSet has changed. The previous type was EnumSet<Flags.Flag>, where Flags.Flag is an enum in the javac class Flags. A recent JDK change has replaced that enum with a new top-level enum called FlagsEnum. It is not possible to change ASTHelpers.asFlagSet in a way that would be type-safe and compatible with the enums from JDKs both before and after the change. Instead, the method now returns ImmutableSet<String>, where the strings come from the toString() of the enum constants. That means they are "native", "abstract", etc.
• Flag IO.print[ln]() in SystemOut.

Full changelog: google/error-prone@v2.41.0...v2.42.0

v2.41.0: Error Prone 2.41.0

New checks:

• EffectivelyPrivate: Detect declarations that have public or protected modifiers, but are effectively private

Changes:

• Skip BooleanLiteral findings if the target type is boxed (#​5134)

Full changelog: google/error-prone@v2.40.0...v2.41.0

v2.40.0: Error Prone 2.40.0

Changes:

• Bug fixes and improvements
• Releases (including snapshots) have migrated from OSSRH to the Central Publisher Portal

Full changelog: google/error-prone@v2.39.0...v2.40.0

v2.39.0: Error Prone 2.39.0

Compare Source

Changes:

• Temporarily downgrade to Guava 33.4.0 (#​5108)

Checks:

• BooleanLiteral: Prefer true to Boolean.TRUE
• ExpensiveLenientFormatString: Renamed from PreconditionsExpensiveString, detects unnecessary calls to String.format in the arguments of lenient formatting methods.
• UnnecessaryQualifier: Detects @Qualifier or @BindingAnnotation annotations that have no effect, and can be removed

Issues: #​4996, #​5045

Full changelog: google/error-prone@v2.38.0...v2.39.0

v2.38.0: Error Prone 2.38.0

Compare Source

New checks:

• AddNullMarkedToPackageInfo: adds @org.jspecify.annotations.NullMarked annotation to package-info files
• IntLiteralCast: Suggests a literal of the desired type instead of casting an int literal to a long, float, or double
• MisleadingEmptyVarargs: Discourages calling varargs methods that expect at least one argument with no arguments, like Mockito's thenThrow
• PreconditionsExpensiveString: Discourages expensive string formatting in Guava Preconditions checks
• SelfSet: Detects mistakes like proto.setFoo(proto.getFoo())
• UnnecessaryCopy: detect unnecessary copies of proto Lists and Maps.

Closed issues: #​4924, #​4897, #​4995

Full changelog: google/error-prone@v2.37.0...v2.38.0

v2.37.0: Error Prone 2.37.0

Changes:

• The annotations that were previously in error_prone_type_annotations have been been merged into error_prone_annotations. error_prone_type_annotations is now deprecated, and will be removed in a future release.

New checks:

• AssignmentExpression - The use of an assignment expression can be surprising and hard to read; consider factoring out the assignment to a separate statement.
• IntFloatConversion - Detect calls to scalb that should be using the double overload instead
• InvalidSnippet - Detects snippets which omit the : required for inline code.
• JUnit4EmptyMethods - Detects empty JUnit4 @Before, @After, @BeforeClass, and @AfterClass methods.
• MockIllegalThrows - Detects cases where Mockito is configured to throw checked exception types which are impossible.
• NegativeBoolean - Prefer positive boolean names.
• RuleNotRun - Detects TestRules not annotated with @Rule, that won't be run.
• StringConcatToTextBlock - Replaces concatenated multiline strings with text blocks.
• TimeInStaticInitializer - Detects accesses of the system time in static contexts.

Closed issues:

• Propagate check flags in patch mode (#​4699)
• Fixes a crash in ComputeIfAbsentAmbiguousReference (#​4736)
• Show the field name in HidingField diagnostics (#​4775)
• Add support for jakarta annotations to some checks (#​4782)
• FloatingPointAssertionWithinEpsilonTest depends on default locale (#​4815)
• @InlineMe patching of Strings.repeat produces broken code (#​4819)
• Fix a crash in IdentifierName on unnamed (_) variables (#​4847)
• Fix a crash in ArgumentParameterSwap (#​490)

Full changelog: google/error-prone@v2.36.0...v2.37.0

v2.36.0: Error Prone 2.36.0

Changes:

• Add new matcher interfaces to ErrorProneScanner for AST nodes introduced after Java 11 (e5fd194)
• Fix compatibility with latest JDK 24 EA builds (d67bc15)
• Check that --should-stop=ifError=FLOW is set when using the -Xplugin integration (e71db1f)

New checks:

• DuplicateBranches: Discourage conditional expressions and if statements where both branches are the same
• RedundantControlFlow: Reports redundant continue statements.

Closed issues: #​4633, #​4646

Full changelog: google/error-prone@v2.35.1...v2.36.0

v2.35.1: Error Prone 2.35.1

Error Prone's dependency on protobuf has been downgraded to 3.25.5 for this release.

Version 3.25.5 of protobuf still fixes CVE-2024-7254. This release is provided for users who aren't ready to update to 4.x, see also #​4584 and #​4634. Future versions of Error Prone will upgrade back to protobuf 4.x.

Full changelog: google/error-prone@v2.35.0...v2.35.1

v2.35.0: Error Prone 2.35.0

Changes:

• Fix handling of \s before the trailing delimiter in MisleadingEscapedSpace
• TimeUnitMismatch improvements: handle binary trees, consider trees like fooSeconds * 1000 to have units of millis

New checks:

• JavaDurationGetSecondsToToSeconds: Prefer duration.toSeconds() over duration.getSeconds()

Full changelog: google/error-prone@v2.34.0...v2.35.0

v2.34.0: Error Prone 2.34.0

Changes:

• Passing the javac flag --should-stop=ifError=FLOW is now required when running Error Prone (#​4595)
• The MemberName check was renamed to IdentifierName

New checks:

• FutureTransformAsync: The usage of transformAsync is not necessary when all the return values of the transformation function are immediate futures.
• MisformattedTestData: Reformats Java source code inside Error Prone test cases.
• MisleadingEscapedSpace: Using \s anywhere except at the end of a line in a text block is potentially misleading.
• ThrowIfUncheckedKnownUnchecked: throwIfUnchecked(knownUnchecked) is equivalent to throw knownUnchecked.

Closed issues: #​4595, #​4598, #​4620

Full changelog: google/error-prone@v2.33.0...v2.34.0

v2.33.0: Error Prone 2.33.0

Similar to release 2.32.0, the minimum supported JDK version to run Error Prone is JDK 17 (#​3803). Using Error Prone to compile code that is deployed to earlier versions is still fully supported, but will require using JDK 17 or newer for compilation and setting --release or -source/-target/-bootclasspath.

Changes:

• Update protobuf version for CVE-2024-7254

New checks:

• ArrayRecordComponent: Record components should not be arrays.

Full changelog: google/error-prone@v2.32.0...v2.33.0

v2.32.0: Error Prone 2.32.0

The minimum support JDK version to run Error Prone is now JDK 17 (#​3803).

Using Error Prone to compile code that is deployed to earlier versions is still fully supported, but will requires using JDK 17 or newer for compilation and setting --release or -source/-target/-bootclasspath.

Full changelog: google/error-prone@v2.31.0...v2.32.0

v2.31.0: Error Prone 2.31.0

This is the last planned minor release of Error Prone that will support running on JDK 11, see #​3803. Using Error Prone to compile code that is deployed to earlier versions will continue to be fully supported, but will require using JDK 17 or newer for compilation and setting --release or -source/-target/-bootclasspath.

Changes:

• Introduce @ThreadSafeTypeParameter with enforcement by ThreadSafe
• Improved support for latest JDK 24 EA builds
• Error Prone is now distributed as a Multi-Release jar (#​3756)

New checks:

• AutoValueBoxedValues: AutoValue instances should not usually contain boxed types that are not Nullable. We recommend removing the unnecessary boxing.

Full changelog: google/error-prone@v2.30.0...v2.31.0

v2.30.0: Error Prone 2.30.0

New checks:

• AutoValueBoxedValues: Detects unnecessary boxing in AutoValue classes.
• DefaultLocale: Detects implicit use of the JVM default locale, which can result in differing behaviour between JVM executions.
• UnnecessaryBreakInSwitch: Remove unnecessary break statements in -> switches.

Closed issues: #​632, #​4487

Full changelog: google/error-prone@v2.29.2...v2.30.0

v2.29.2: Error Prone 2.29.2

This release contains all of the changes in 2.29.0 and 2.29.1, plus:

• a bug fix for a crash in TraditionalSwitchExpression (#​4479)
• restores the module-info for the annotations jar, which was accidentally removed (#​4480)

Full Changelog: google/error-prone@v2.29.1...v2.29.2

v2.29.1: Error Prone 2.29.1

This release contains all of the changes in 2.29.0, plus:

• a bug fix to UnusedVariable to handle unnamed _ variables (#​4451)
• a bug fix for a crash in SetUnrecognized (#​4475)

Full Changelog: google/error-prone@v2.29.0...v2.29.1

v2.29.0: Error Prone 2.29.0

New checks:

• MissingRuntimeRetention
• SetUnrecognized
• StatementSwitchToExpressionSwitch

Closed issues: #​4318, #​4429, #​4467

Full Changelog: google/error-prone@v2.28.0...v2.29.0

v2.28.0: Error Prone 2.28.0

Error Prone nows supports the latest JDK 23 EA builds (#​4412, #​4415).

Closed issues:

• Improved errors for invalid check severities (#​4306).
• Fix a crash with nested instanceof patterns (#​4349).
• Fix a crash in JUnitIncompatibleType (#​4377).
• In ObjectEqualsForPrimitives, don't suggest replacing equal with == for floating-point values (#​4392).

New checks:

• DeeplyNested discourages very deeply nested code that can cause StackOverflowErrors during compilation.
• GuiceNestedCombine discourages nesting of Modules.combine(), which is unnecessary.
• PatternMatchingInstanceof migrates code to use pattern matching for instanceof
• SunApi discourages use of internal proprietary JDK APIs which may be removed from future releases.

Full Changelog: google/error-prone@v2.27.1...v2.28.0

v2.27.1: Error Prone 2.27.1

This release contains all of the changes in 2.27.0, plus a bug fix to ClassInitializationDeadlock (#​4378)

Full Changelog: google/error-prone@v2.27.0...v2.27.1

v2.27.0: Error Prone 2.27.0

New checks:

• ClassInitializationDeadlock detects class initializers that reference subtypes of the current class, which can result in deadlocks.
• MockitoDoSetup suggests using when/thenReturn over doReturn/when for additional type safety.
• VoidUsed suggests using a literal null instead of referring to a Void-typed variable.

Modified checks:

• TruthSelfEquals has been renamed and generalized as SelfAssertion
• RedundantSetterCall has been improved, and enabled as an error oby default

Closed issues: #​4291. #​4308, #​4343, #​4320

Full Changelog: google/error-prone@v2.26.1...v2.27.0

v2.26.1: Error Prone 2.26.1

This release contains all of the changes in 2.26.0, plus a bug fix to the module name of the annotations artifact com.google.errorprone.annotations (9d99ee7)

Starting in 2.26.x, the 'annotations' artifact now includes a module-info.java for Java Platform Module System support, thanks to @​sgammon in #​4311.

Compatibility note:

Now that the annotations artifact explicit declares a module instead of relying on Automatic-Module-Name, JDK 17 and newer perform stricter module encapsulation checks. Modularized libraries depending on Error Prone annotations 2.26.x and newer may see errors like:

error: package com.google.errorprone.annotations is not visible
import com.google.errorprone.annotations.CheckReturnValue;
                            ^
  (package com.google.errorprone.annotations is declared in module com.google.errorprone.annotations, but module ... does not read it)

The fix is to add requires static to the module declaration of modularized libraries that depend on Error Prone annotations:

 module your.module {
...
+  requires static com.google.errorprone.annotations;
 }

Full Changelog: google/error-prone@v2.26.0...v2.26.1

v2.26.0: Error Prone 2.26.0

Warning: This release contains a bug, please use 2.26.1 or newer instead.

Changes:

• The 'annotations' artifact now includes a module-info.java for Java Platform Module System support, thanks to @​sgammon in #​4311.
• Disabled checks passed to -XepPatchChecks are now ignored, instead of causing a crash. Thanks to @​oxkitsune in #​4028.

New checks:

• SystemConsoleNull: Null-checking System.console() is not a reliable way to detect if the console is connected to a terminal.
• EnumOrdinal: Discourage uses of Enum.ordinal()

Closed issues: #​2649, #​3908, #​4028, #​4311, #​4314

Full Changelog: google/error-prone@v2.25.0...v2.26.0

v2.25.0: Error Prone 2.25.0

New checks:

• JUnitIncompatibleType: Detects incompatible types passed to an assertion, similar to TruthIncompatibleType
• RedundantSetterCall: Detects fields set twice in the same chained expression. Generalization of previous ProtoRedundantSet check to also handle AutoValue.

Closed issues: #​4195, #​4224, #​4228, #​4248, #​4249, #​4251

Full Changelog: google/error-prone@v2.24.1...v2.25.0